How Do Behavioral Context and Internal State Influence Sensory Perception and Behavior?

Prof. Dr. Ilona Grunwald Kadow was interviewed by Latest Thinking to talk about her research.

Research of the Grunwald-Kadow Lab

Here you can find a selection of our research projects. Please click on the + sign on the top right of each article to find out more.

The taste neurons in the leg of the fruit fly are activated via two types of polyamine receptors. This helps the fly to choose food and good egg-laying sites.
© MPI of Neurobiology/L. Loschek

May 04, 2016

The amount and composition of nutrients required by the body vary according to its state and physiological circumstances. Polyamines, for example, are needed in greater quantities whenever tissues develop, grow or regenerate. Low polyamine levels are associated with neurodegenerative diseases, ageing and fertility decline. Excess polyamines, however, may play a role in the development of cancer. Together with colleagues from Sweden, scientists from the Max Planck Institute of Neurobiology in Martinsried have now identified the receptors enabling insects to recognize polyamines in food. The study suggests that the ability to identify polyamines via the senses of taste and smell could have influenced animal survival and reproduction.


The reproductive state of the female fly sends signals to the brain, after which the sensory perception changes. The image shows part of the reproductive system with the uterus of the female fly.
© MPI of Neurobiology/ Friedrich

May 04, 2016

The perception and reactions to odours and tastes can change in pregnancy, sometimes dramatically. This is also true for flies. The mechanisms, however, that trigger these changes are not understood in either mammals or insects. Scientists from the Max Planck Institute of Neurobiology in Martinsried now succeeded in demonstrating that the concentration of a certain receptor increases in the sensory organs of gravid fruit fly females. As a result, the taste and odour of important nutrients, called polyamines, are processed differently in the brain: Pregnant flies favour nutrition that is rich in polyamines and increase their reproductive success in this way.


Nerve cells that use dopamine as a neurotransmitter (green) enable hungry flies to ignore danger signs and modulate their innate behaviour.
© MPI of Neurobiology/ Friedrich

August 20, 2015

For most of us, a freshly brewed cup of coffee smells wonderful. However, individual components that make up the fragrance of coffee can be extremely repulsive in isolation or in a different combination. The brain therefore relativizes and evaluates the individual components of a fragrance. Only then is an informed decision possible as to whether an odour and its source are “good” or “bad”. Scientists from the Max Planck Institute of Neurobiology in Martinsried have discovered how conflicting smells are processed in the mushroom body of the brain of the fruit fly. The results assign a new function to this brain region and show that sensory stimuli are evaluated in a situation-dependent context. In this way the insects are able to make an appropriate decision on the spur of the moment.


This projection neuron forwards carbon dioxide information to the region in the fly's brain where the animals can gauge internal and external signals.
© MPI for Neurobiology / Purayil & Kadow

June 25, 2013

Hungry people are often difficult to deal with. A good meal can affect more than our mood, it can also influence our willingness to take risks. This phenomenon is also apparent across a very diverse range of species in the animal kingdom. Experiments conducted on the fruit fly, Drosophila, by scientists at the Max Planck Institute of Neurobiology in Martinsried have shown that hunger not only modifies behaviour, but also changes pathways in the brain.